dfn.de

Checked 21 October 2026, 22:14 UTC · via 8.8.8.8
iAll checks passed
27 passed 0 warnings 0 failed 6 info

Registration

info

.de country-code

Found

TLD
.de (country-code)
ICANN policies apply
no

Checks

  • i
    .de is a country-code TLD (ccTLD)
    Country-code TLD: governed by its local registry under national policy, not by an ICANN contract. Registrar accreditation, dispute resolution and RDAP/WHOIS rules are set by the registry.
    #1
  • ✓ TLD delegated and signed #2
    .de is delegated in the root zone and DNSSEC-signed.
  • i
    Registration data not available
    No registration data via RDAP: the registry of .de offers no RDAP service. Many ccTLD registries don't offer RDAP; check the registry's WHOIS instead.
    #3

Delegation

info

ns1.dfn.de, ns2.dfn.de, ns3.dfn.de, ns4.dfn.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns1.dfn.de, ns2.dfn.de, ns3.dfn.de, ns4.dfn.de
NS in the zone
ns1.dfn.de, ns2.dfn.de, ns3.dfn.de, ns4.dfn.de
NameserverAddressesNetwork (AS)Glue
ns1.dfn.de194.95.236.51 2001:638:d:c110::51AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.95.236.51 2001:638:d:c110::51
ns2.dfn.de194.95.236.59 2001:638:d:c111::59AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.95.236.59 2001:638:d:c111::59
ns3.dfn.de194.95.236.67AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.95.236.67
ns4.dfn.de202.61.237.185 2a03:4000:5c:da8::185AS197540 netcup-AS - netcup GmbH, DE AS197540 netcup-AS - netcup GmbH, DE202.61.237.185 2a03:4000:5c:da8::185

Checks

  • ✓ 4 nameservers #6
    Delegated to ns1.dfn.de, ns2.dfn.de, ns3.dfn.de, ns4.dfn.de.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: ns1.dfn.de, ns2.dfn.de, ns3.dfn.de, ns4.dfn.de.
  • ✓ All names resolve #9
    Every nameserver name has an address and is not an alias.
  • ✓ Nameservers in different networks #10
    The nameservers are spread over 2 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS197540 (netcup-AS - netcup GmbH, DE): 2 addresses; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 5 addresses.
  • i
    All nameserver names under .de
    All nameserver names are under one TLD, so a problem with that TLD also makes the nameservers unreachable. Some operators use names under two TLDs for extra resilience.
    #12
  • i
    Partly IPv6
    These nameservers have no IPv6 address: ns3.dfn.de.
    #13

Nameservers

pass

7 of 7 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.dfn.de 194.95.236.51NOERROR, 7 ms, authoritativenoyes / yesrefused-
ns1.dfn.de 2001:638:d:c110::51NOERROR, 7 ms, authoritativenoyes / yesrefused-
ns2.dfn.de 194.95.236.59NOERROR, 8 ms, authoritativenoyes / yesrefused-
ns2.dfn.de 2001:638:d:c111::59NOERROR, 8 ms, authoritativenoyes / yesrefused-
ns3.dfn.de 194.95.236.67NOERROR, 14 ms, authoritativenoyes / yesrefused-
ns4.dfn.de 202.61.237.185NOERROR, 0 ms, authoritativenoyes / yesrefused-
ns4.dfn.de 2a03:4000:5c:da8::185NOERROR, 0 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 7 nameserver addresses answered.
  • ✓ All authoritative #15
    Every responding nameserver answers authoritatively for the zone.
  • ✓ No recursion #16
    The nameservers do not answer recursive queries for other domains.
  • ✓ No version disclosed #17
    The nameservers don't reveal their software version.
  • ✓ Zone transfers refused #18
    No nameserver allows a zone transfer to the public.
  • ✓ TCP supported #19
    All nameservers answer over TCP.
  • ✓ EDNS supported #20
    All nameservers support EDNS(0).
  • ✓ Public addresses #21
    All nameserver addresses are publicly routable.

SOA

pass

serial 1792570490 · primary ns1.dfn.de

Found

Primary (MNAME)
ns1.dfn.de
Contact (RNAME)
hostmaster.dfn.de
Serial
1792570490
Refresh / retry
28800 s / 7200 s
Expire
3024000 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
ns1.dfn.de (194.95.236.51)1792570490
ns1.dfn.de (2001:638:d:c110::51)1792570490
ns2.dfn.de (194.95.236.59)1792570490
ns2.dfn.de (2001:638:d:c111::59)1792570490
ns3.dfn.de (194.95.236.67)1792570490
ns4.dfn.de (202.61.237.185)1792570490
ns4.dfn.de (2a03:4000:5c:da8::185)1792570490

Checks

  • ✓ Serial 1792570490 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 35d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.dfn.de is one of the listed nameservers.
  • ✓ Contact hostmaster@dfn.de #25
    The SOA RNAME hostmaster.dfn.de means hostmaster@dfn.de.
  • ✓ Timestamp serial #26
    The serial 1792570490 is a Unix timestamp (2026-10-21 08:14 UTC).

DNSSEC

info

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC
Signatures valid until
5 November 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
52345ECDSAP256SHA256 (13)SHA256 CB45E805D6DE033C…yes

DNSKEY in the zone

Key tagRoleAlgorithm
15867ZSK (256)ECDSAP256SHA256 (13)
52345KSK (257)ECDSAP256SHA256 (13)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 52345 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • ✓ Signatures valid until 2026-11-05 #30
    The earliest DNSKEY/SOA signature expires at 2026-11-05 15:27 UTC.
  • i
    NSEC
    The zone uses NSEC, so its full contents can be listed by walking the NSEC chain. That is fine unless the names are sensitive.
    #31

Records

info

14 records at the apex

Found

Read from
194.95.236.51:53
TypeValueTTL
SOAns1.dfn.de. hostmaster.dfn.de. 1792570490 28800 7200 3024000 360086400
NSns1.dfn.de.86400
NSns3.dfn.de.86400
NSns2.dfn.de.86400
NSns4.dfn.de.86400
A37.208.106.10586400
AAAA2a00:d0c0:c:2109::1186400
MX10 a1001.mx.srv.dfn.de.86400
MX10 b1001.mx.srv.dfn.de.86400
MX10 c1001.mx.srv.dfn.de.86400
TXT"v=spf1 include:_spf.s1004.mx.srv.dfn.de a:deneb.dfn.de include:_spf.dfn-cert.de include:_spft.telekom.com ~all"86400
TXT"google-site-verification=aNjf9WiXv4G4mjXnYovwIjOS01qfUjBGQbV5xomVJ44"86400
TXT"apple-domain-verification=TdQByV6omDQj06SD"86400
TXT"google-site-verification=AHsv25T5W2sYiYNmYvU6z8a2G1H_7FM0vJOZf5uOhAE"86400

Checks

  • ✓ TTLs within range #32
    TTLs: A 1d, AAAA 1d, MX 1d, NS 1d.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • i
    No CAA records
    Without CAA records any certificate authority may issue certificates for this domain. A CAA record limits issuance to the CAs you use.
    #35